Self releasing chain hook



Nov. 19, 1957 w. P. HUTCHINSON 2,813,744

SELF RELEASING CHAIN HOOK 2 Sheets-Sheet 1 Filed Nov. 24, 1953 INVENTOR. W/u/AM Pfi/Wc/w/vw/v BY w/w Nov. 19, 1957 w. P. HUTCHINSON SELF RELEASING CHAIN HOOK 2 Sheets-Sheet 2 Filed NOV. 24. 1953 EZEIM INK IN VEN TOR. [4040/1/14 Pflurcw/vw/v BY %//x% United States Patent SELF RELEASING CHAIN HOOK William P. Hutchinson, Lakewood, Ohio, assignor to Republic Steel Corporation, Cleveland, Ohio, a corporation of New Jersey Application November 24, 1953, Serial No. 394,032

4 Claims. (Cl. 294-75) This invention relates to hoisting apparatus, and, more particularly, to a self-releasing hoisting connection.

In the handling of the type of load which may be sup- 'Various devices for releasing the hoisting chain or bail, which has been used to support the load during the hoisting operation, have been devised. Some of these require a manual release, such as the pulling of a lanyard, for operating a mechanism to force the chain from the hoisting hook. Others have provided various spring devices which invert the hoisting hook to a position to drop the chain when the load on the hook is released. Still others have arranged the hook connection in a counter balance arrangement with an overbalance above the hoisting hook so that when pressure is relieved on the hook, the hook is inverted to release the bail or hoisting chain. Another arrangement has been for the hoisting connection to release the lifting chain by having a member come in contact with the ground or the load and through connecting linkage invert the hoist hook to release the chain.

Frequently, it is not desirable or possible to operate a hoisting connection release by the manual operation of a lanyard or other release mechanism because of the confined quarters in which the load is to beplaced or because of the danger to the individual, who must operate release, being hurt by rolling or tumbling elements of the released load. In the case of the devices which employ springs and in which the hoist connection depends on an over-balance, there is always the danger of releasing the load prematurely if'there is a momentary relaxation of the load pressure on the hoisting hook. Such relaxation of load pressure may occur during the hoisting operation and may result in dropping the load. In the case of the releasing devices which depend on the contact with the load and which invert the hook, through connecting linkage, such devices have required many moving parts which are subject to breakdown and require considerable maintenance. Furthermore, they operate to invert the hook so that there is the danger of jamming in the event that the chain connected to the load may not have relaxed sufiiciently prior to the swiveling of the book.

It is an important object of this invention to provide a self-releasing hoist connection having a minimum number of parts and which can be ruggedly constructed so as to withstand rough usage and which will act positively to release the chain from the hook connection only when the load has been lowered to the ground or other unloading area.

Another object of this invention is to provide a device which does not require any springs or other complicated mechanism and which does not require the inverting of the hook in order to release the hoisting chain or bail which is held in the hook.

The invention includes a self-releasing hoist connection comprising a body member connected at one end to a hoist apparatus and having a recess such as a hook formed therein for releasably receiving a chain or bail, a releasing means connected to said body member and moveable with respect thereto, said releasing means having load contacting means for moving the releasing member with respect to the body member and having means for camming the hoist element from the recess of the body member when the releasing member is moved with respect to the body member.

For a more complete description of the invention, reference is made to the drawings wherein:

Fig. 1 is a perspective view of apparatus embodying the invention;

Fig. 2 is a side view of the body member of the apparatus of this invention with its related parts, in the hoisting position;

Fig. 3 is a side view of the body member and its related parts in the chain releasing position;

Fig. 4 is a sectional view taken along the line 4-4 in Fig. 2; and

Fig. 5 is a view taken along the line 5-5 in Fig. 2, showing the relation of the releasing member to the body member adjacent the hook in the body member.

The self-releasing hoisting apparatus of this invention includes a body member 10, a releasing member 11 slidably mounted on said body member 10. The body member 10 may be provided with a means near its upper end for connecting it to a hoisting apparatus. Suitable connecting means may be eye 12 formed in the body member through which a ring 13 passes, the ring 13 being adapted for connection to a standard hoisting member such as the hook 15 attached to the lower block 16, illustrated in Fig. l. The body member 10 may comprise a plate -member of steel or other relatively strong material which may have at least one hook-like recess 17 formed therein.

The releasing member 11 may be formed of a pair of plate members 18 for slidably engaging both faces of the body member 10. The plates 18 of'the releasing member 11 are welded at their lower ends to a foot plate '20 which is horizontally disposed. The releasing memthe plate 10.

Suitable braces 26 may be provided between the outer faces of the plates 18 and the upper face of the foot 20 in order to give the releasing member suflicient strength so that the apparatus will be able to, stand rough treatment.

The slots 23'define the movement of the releasing member 11 with regard to the body member 10. In the normal hoisting position, the eye 12 and the ring 13 are at the upper end of the body member 10 and the releasing member 11 depends below the body member 10, as shown in Figs. 1, 2 and 4. The releasing member 11 may be moved to an upper position shown in Fig. 3. In moving from the lower position illustrated in Fig. 2 to the upper position illustrated in Fig. 3, cam surfaces 27 provided on each of the plates 18 of the releasing member 11 move from the lower closed end of the hooked recess 17 to the open upper end of such recess, thereby camming any object from such recess, as will be more fully described with regard to the operation of the device.

In the specific apparatus shown, the body member is provided with a second hooked recess 28 so that the two recesses 17 and 28 may receive links of a chain sling 29 adjacent the ends of the sling. The hooks are in the form of narrow slots adapted to receive a chain link edgewise, the chain being held in the hook against slipping by reason of the adjacent links being disposed so as to prevent the link in each slot from sliding out, as best illustrated in Fig. 5.

In order to connect the hoisting apparatus to a load, the body member is connected to a standard hoisting hook 15in an arrangement such as that shown in Fig. 1. One of the links adjacent one end of the chain 29 is then passed into the slot 28, the chain is thereafter passed around the load, e. g. pipe 30, and a link adjacent the other end of the chain is placed in the hook recess 17 in the manner shown. For a proper connection of the ends of the chain, and particularly the positioning of the chain in the slot 17, the hoisting apparatus should be suspended somewhat above the load so that the releasing member 11 is in its lower depending position, as shown in Figs. 1, 2 and 4. After the hoisting operation, when the load has been deposited at the place where it is to be unloaded, the hoisting apparatus is lowered beyond the point where the weight of the load is released and the foot portion 20 of the releasing member is brought into contact with the load, as shown in Fig. 3.

and the body member continues to descend, causing the cam surfaces 27 of the releasing member 11 to engage the chain on both sides of the hook recess 17 and push it from such recess.

The foot portion 20, as shown, may be made of suitable length and width so that it will support the releasing member in a stable manner and will not tend to fall over as it rests on the load.

It will be appreciated that the invention described herein will fulfill the objects of providing a self-releasing hoist connection having a minimum number of parts which can be ruggedly constructed so as to withstand rough usage and which will act positively to release the chain from the hook connection only when the load has been lowered to the ground or other unloading area, and of providing a device which does not require any springs or other complicated mechanism and which does not require the inverting of the hook in order to release the hoisting chain or bail which is held in the book.

In accordance with the provisions of the patent statutes, I have herein described the principle of operation of the invention, together with the elements which I now consider the best embodiments thereof, but I desire to have it understood that the structure disclosed is only illustrative and the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combinations and relations described, some of these may be altered and modified without interfering with the more general results outlined.

Having thus described my invention, I claim:

1. A self-releasing hoist connection comprising a centratplate member having means at one end for connec- As the, foot 20 contacts the load, the releasing member 11 is held tion to hoisting apparatus, and having at least one hook recess formed below the connection means, a releasing means comprising two plates slidably mounted on each of the faces of the plate member, the two plates of the releasing means being supported in parallel relationship to each other and depending below the plate member when said plate member is supported by hoisting apparatus and load engaging means connected to the releasing means whereby the releasing means may be supported on a load so that the plate member and releasing means may be moved slidably'with respect to each other. cam means on the two plates of the releasing means operable for removing elements disposed in the hook recess of the plate member, by the continued downward movement of the plate member with the releasing means supported by the load.

2. The apparatus of claim 1 wherein the plate member is formed with at least one slot and the plates of the releasing meansare connected to pins which are slidably mounted in said slot, the movement of the pins in the slots defining. the movement of the releasing means with respect to the plate member.

3,. The apparatus of claim 1 wherein the plate member has a second hook recess. arranged in complementary relationship to the first hook recess with respect to the means for connection to the hoisting apparatus whereby two portions of a chain hoisting sling may be connected to the plate member, one of said portions in each recess.

4. A self-releasinghoist connection comprising a plate member having means at one end for connection to hoisting apparatus, an upwardly opening chain slot formed in said plate member below the connecting means, chain releasing plate means secured to said plate member for limited vertical sliding movement thereon, a

load-engaging portion of said chain releasing plate means. extending below said plate member adapted to contact. a. load prior to contact thereof by said plate member whereby they plate member and releasing plate means are caused to slide upon each other, said chain releasing plate means including a cam surface disposed below saidslot when said plate means is in non-releasing position, said cam surface on said releasing plate means being operable, to engage and release a chain located in said chain slot upon the continued downward movement of said plate member with the chain releasing plate means supported by a load.

References Cited in the file of this patent UNITED STATES PATENTS 318,558 Gardiner May 26, 1885 1,862,312 Kositzky June 7, 1932 1,994,646 Heath a Mar. 19, 1935 

